000 AXPZ20 KNHC 051514 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1514 UTC Fri Oct 5 2018 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Hurricane Sergio centered near 15.9N 121.8W at 05/1500 UTC or 800 nm WSW of the southern tip of Baja California moving W at 7 kt. Estimated minimum central pressure is 959 mb. Maximum sustained wind speed is 100 kt with gusts to 120 kt. Numerous moderate and isolated strong convection is within 180 nm in the NE and SW quadrants and within 150 nm in the SE and NW quadrants of Sergio. A band of scattered moderate convection is also between 180 nm and 240 nm in the SE quadrant, with a band of scattered moderate and isolated strong convection between 270 nm and 450 nm in the SE quadrant as well. Large swell generated from Sergio will impact the Pacific coast of Mexico and southern California through this weekend. Slow weakening is forecast during the next several days, but Sergio is expected to remain a hurricane through the middle of next week. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP1/WTPZ31 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 12N85W to low pressure near 11.5N94.5W to 11N105W to 16N113W then resumes from 12N123W to 10N140W. Scattered moderate and isolated strong convection is within 180 nm either side of the axis between 85W and 94W and also within 240 nm between 95W and 100W. Scattered moderate convection is from 11N to 14N between 105W and 109W, from 08N to 10.5N between 125W and 130W, from 10N to 12.5N between 130W and 136W, and also from 08.5N to 11.5N between 134W and 137W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for details on Hurricane Sergio. Mainly moderate to fresh NW to N winds and mixed swells from Sergio and long period NW swell will support combined seas of 7 to 11 ft to the W of 110W building early next week, and 5 to 8 ft E of 110W. In the Gulf of California, a tight pressure gradient will develop from 29N to 31N Sat evening through Sun night and SW to W winds will rapidly increase to fresh to near gale force enhanced from gap wind flow in Baja California Norte. Model guidance indicates possible gale force winds which will be monitored today in case a gale warning becomes required. Otherwise, gentle to moderate winds will prevail into early next week. In the Gulf of Tehuantepec, fresh to strong gap winds will prevail through early Sat. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong SW monsoonal flow and 8 to 10 ft seas, are expected roughly from 08N to 12N and E of 95W the next few days in response to a broad area of low pressure over Central America, called a Central American Gyre. As is typical for these features, the associated long fetch of SW winds across the tropical Pacific will transport abundant moisture into portions of Central America, especially from Costa Rica to Honduras. This will create the potential for significant rainfall over these areas through early next week. Refer to your local meteorological service for specific information on this potentially dangerous weather pattern. REMAINDER OF THE AREA... Please see the Special Features section for details on Hurricane Sergio. Elsewhere, moderate to fresh trades will prevail outside of the influence of Sergio. The pressure gradient will tighten across the northern waters early next week with N to NE flow around a deepening high NW of the area supporting an increase to fresh to strong winds along and N of 30N. Meanwhile, confused seas are likely to continue due to long period NW swell and large and expanding area of mixed swell associated with Sergio. $$ Lewitsky